SHIJIAZHUANG, CHINA—A cluster of more than 80 tombs in northern China has so far yielded more than 300 artifacts dating from the West Han Dynasty (206 B.C.­24 A.D.) and the Tang Dynasty (618­907), including pottery, porcelain, and bronzes. Archaeologist Zhang Xiaozheng, head of the excavation, says that the artifacts reflect the daily lives of ordinary people.